Sorry for the bad english, it’s a Google translation, I am German and I live in sweden.
My problem:
In the datasheet of EM406A following output messages are defined:
NMEA 0183 GGA, GSA, GSV, RMC, VTG, GLL.
But I can only receive GGA, RMC and GSA. I need urgently VTG however. Even in a moving car, I received no VTG.
The same problem I have with a EM411 (supposedly identical with EM406A).
Can someone tell me what should I do to receive VTG ?
Bernd
Read page-25 of this NMEA manual:
Thanks fll-freak,
on page 23 (http://www.sparkfun.com/datasheets/GPS/ … anual1.pdf) I found this:
2.Enable VTG message for a 1 Hz constant output with checksum enabled
$PSRF103,05,00,01,01*20
I’ve read through all this and understood. But what I do now with $PSRF103,05,00,01,01*20 ?
Must be sent with eg Serial.print to the EM406A ?
Questions, questions …
Maybe someone has a code snippet for the IDE 0022/1.0.1?
The helpless Bernd
That was a typo. Should have been logical page 2-5 or as you discovered physical page 23.
If you sent that string to the GPS, it should start sending the VTG. If you are using Arduino, than a Serial.print would be a logical choice. Might need a terminator like \n or \r. If you are using a GPS library it MIGHT be the case there is a method to call. Since I have not used the NMEA interface on a GPS before (I much prefer binary interfaces) I can’t help you there.
Because no one has yet used $GPVTG ?
With the IDE0022 I have tried the following:
#include <NewSoftSerial.h>
NewSoftSerial NSS(2,3);
String VTG;
//*********************************
void setup()
{
Serial.begin(9600);
NSS.begin(4800);
//VTG=“$PSRF103,05,00,01,01*20”+‘\n’;
//VTG=“$PSRF103,05,00,01,01*20”+‘\r’;
VTG=“$PSRF103,05,00,01,01*20”;
NSS.print(VTG);
}
//*********************************
void loop()
{
//Code
}
With all three types of VTG I tried it, it does not work. The rest of the code (with $GPGGA, $GPRMC, $GPGGA, hidden here) works fine for months. I just want to embed only $GPTVG addition.
Where are the experts ? From GlobalSat, the maker of EM406A, I got no response.
SOS, please help me.
Bernd
By the way: Is $GPTVG constantly read or only if EM406A is in motion?
So here is the solution:
#include <NewSoftSerial.h>
NewSoftSerial NSS(2,3);
char PSRF[26];
String string1,string2,string3,string4;
//*********************************
void setup()
{
Serial.begin(9600);
NSS.begin(4800);
string1=String(“$PSRF103,05,00,01,01*20”);
string2=String(‘\r’);
string3=String(‘\n’);
string4=string1+string2+string3;
string4.toCharArray(PSRF,26);
Serial.print(““);Serial.print(PSRF);Serial.println(””);
NSS.print(PSRF);
delay(200);
}
//*********************************
void loop()
{
//Code
}
follows:
$GPGGA,164626.000,5658.4493,N,01538.2431,E,1,08,1.0,179.0,M,32.5,M,0000*50
$GPGSA,A,3,11,14,31,19,17,20,23,01,1.7,1.0,1.3*3C
$GPRMC,164626.000,A,5658.4493,N,01538.2431,E,0.11,70.21,231012,A*57
$GPVTG,70.21,T,M,0.11,N,0.2,K,A*3B
1000 thanks to fribbe (http://www.macherzin.net)
Happy Bernd
Happy Bernd on Brickamovagen road!